/*
 * Copyright (c) 2023-2025 elsfs Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.elsfs.cloud.common.mybatis.ext.sql.support.common;

import com.baomidou.mybatisplus.core.metadata.TableInfoHelper;
import java.util.HashMap;
import java.util.Map;
import org.elsfs.cloud.common.mybatis.ext.sql.TableAliasManager;

/** 简单表别名管理器 */
public class SimpleTableAliasManager implements TableAliasManager {

  /** 别名Map */
  private final Map<String, String> aliasMap = new HashMap<>();

  /** 计数器 */
  private int index;

  /**
   * 生成表别名
   *
   * @param entityClass 表实体类
   * @return 别名
   */
  @Override
  public String generateAlias(Class<?> entityClass) {
    return this.generateAlias(TableInfoHelper.getTableInfo(entityClass).getTableName());
  }

  /**
   * 生成表别名
   *
   * @param table 数据库表名
   * @return 别名
   */
  @Override
  public String generateAlias(String table) {
    if (this.aliasMap.containsKey(table)) {
      return this.aliasMap.get(table);
    }

    String alias;
    do {
      alias = "t" + this.index++;
    } while (this.aliasMap.containsKey(alias));

    this.aliasMap.put(table, alias);
    return alias;
  }

  /**
   * 注册表别名
   *
   * @param entityClass 表实体类
   * @param alias 别名
   */
  @Override
  public void registerAlias(Class<?> entityClass, String alias) {
    this.aliasMap.put(TableInfoHelper.getTableInfo(entityClass).getTableName(), alias);
  }

  /**
   * 注册表别名
   *
   * @param table 数据库表名
   * @param alias 别名
   */
  @Override
  public void registerAlias(String table, String alias) {
    this.aliasMap.put(table, alias);
  }

  /**
   * 获取表别名
   *
   * @param entityClass 表实体类
   * @return 表别名
   */
  @Override
  public String fetchTableAlias(Class<?> entityClass) {
    return this.fetchTableAlias(TableInfoHelper.getTableInfo(entityClass).getTableName());
  }

  /**
   * 获取表别名
   *
   * @param table 数据库表名
   * @return 表别名
   */
  @Override
  public String fetchTableAlias(String table) {
    return this.aliasMap.get(table);
  }
}
